Microvalves and pumps are essential components for many microfluidic bioanalysis applications including genomic analysis, pathogen detection, immunoassays, high-throughput cellular analysis and automated sample processing. Mechanisms for microvalve actuation including electrical, thermal, chemical and pneumatic means have been developed and utilized for sample delivery and flow rate control. See, e.g. Oh, K. W., Ahn, C. H., J. Micromech. Microeng. 2006, 16, R13-R39. Pneumatically-actuated microvalves and pumps have been most widely employed for assay automation with large scale integration because this fabrication is simple and inexpensive. But the efficiency, portability, and reusability of pneumatically-actuated microvalves and pumps all leave room for improvement.